Image sensors can be coupled with invisible-wavelength filters so that they can capture images at wavelengths outside the visible range of wavelengths, for instance in the infrared (IR) wavelength range. Two kinds of materials are used to make existing infrared filters: pigment-based materials and C-based materials. Pigment-based infrared filters are usually used in image sensors with pixel sizes less than 1.4 μm. They have high infrared transmittance that translates to a higher signal-to-noise ratio (SNR), but they cannot completely block visible wavelengths like blue and red so they create worse color error. C-based infrared filters are usually used in image sensors with pixel sizes greater than 1.4 μm. They completely block visible wavelengths like blue and red and so have smaller color error, but they have low infrared transmittance which translates into a lower SNR.